This application is the national phase of international application PCT/JP97/01116 filed Mar. 31, 1997 which designated the U.S.
1. Field of the Invention
The present invention relates to a vehicle lock apparatus, and more particularly to a vehicle lock apparatus having a wireless door lock system remotely controlling a look mechanism of a vehicle and an immobilizer switching a state of a vehicle between a state in which the vehicle can start and a state in which the vehicle can not start.
2. Background of the Invention
Conventionally, a technique by which a wireless door look apparatus and an anti-theft system are combined has been known, as indicated, for example, in Japanese Laid-Open Patent Application No. 2-161085. In the above conventional apparatus, the wireless door lock apparatus has a wireless transmission unit provided in a key, a door lock mechanism provided in a vehicle and a warning unit issuing a warning under a predetermined condition.
The wireless sending unit uses a battery provided in the key as a power supply. When a sending switch is operated, the wireless sending unit sends a wireless signal including a predetermined ID signal. The door lock mechanism provided in the vehicle locks and unlocks the door when the ID signal included in the wireless signal is equal to an ID signal assigned to the vehicle. The warning until its switched from an active state to an inactive state when the door is unlocked in response to the wireless signal. In addition, the warning unit in switched from the inactive state to the, active state when the door is locked.
As has been described above, according to the above apparatus, based on a function of the wireless door lock apparatus, the lock state of the door and the state of the warning unit can be remotely controlled. Thus, according to the conventional apparatus, the state of the warning unit can be securely and pertinently switched without reducing the facility.
An apparatus disclosed for example, in Japanese Laid-Open Patent Application No. 63-63875 has been conventionally known as an apparatus electrically forming a function of a key in the same manner as the wireless door lock apparatus. The above conventional apparatus has a transponder provided in a key and an antenna-coil provided near a key cylinder. The transponder is provided with a coil forming an electromagnetic coupling circuit in conjunction with the antenna-coil when the key is inserted into the key cylinder and a rectifier circuit connected to the coil.
An AC voltage having a predetermined frequency is applied between both ends of the antenna-coil. When the AC voltage is applied between both ends of the antenna-coil, an AC voltage in generated in the coil of the transponder by electromagnetic induction. The AC voltage generated between both ends of the coil is converted into a DC voltage by the rectifier circuit. The transponder uses the DC voltage generated as described above as a power supply and sands an electromagnetic in signal inducting a predetermined ID signal.
The electromagnetic signal sent by the transponder ie received by the antenna-coil. The conventional apparatus has a demodulation circuit demodulating the electromagnetic signal received by the antenna-coil and an unlock mechanism unlocking a lock when the ID signal included in the demodulated signal is equal to an ID signal assigned to a vehicle. Thus, according to the above conventional apparatus, the lock can be unlocked only when the proper key is inserted into the key.
In the wireless door lock apparatus and the lock apparatus using the transponder as described above, it is determined whether the ID signal sent from the key is equal to an ID signal assigned to the vehicle. If the ID code of the key is equal to the ID code of the vehicle, a computer used to control an engine, is controlled to be in an active state. If the ID codes are not equal to each other, the computer is controlled to be in an inactive state. Due to the above control of the computer, the active/inactive state of the vehicle can be controlled based on the above determination result. As has been described above, the sending of the ID signal using the wireless signal or the electromagnetic signal as a medium is effective for the control of the lock state of the vehicle and for the control of the active/inactive state of the vehicle.
However, in a case where the ID signal is sent using the wireless signal, although there is an advantage in that a relatively long communication distance can be secured, there is a disadvantage in that a large amount of electric power is needed to send the wireless signal, so that communication can not be performed using energy of a power supply from the vehicle side. Thus, in a cage where the active/inactive state of the vehicle is controlled using the wireless signal, if the battery provided in the key has been consumed, the inactive state of the vehicle can not be removed in spite of using the proper key.
In a case where the ID signal is sent using the electromagnetic signal transmitted by the transponder, although there is an advantage in that communication can be performed using energy of a power supply from the vehicle side, there is a disadvantage in that only a very short communication distance ie secured. Thus, a function for remotely controlling the door look may not be formed according to a constitution for sending the ID signal using the electromagnetic signal.
Thus, in order to secure superior facility regarding lock and unlock operations of the door and electrically control the active/inactive state of the vehicle, both a system for controlling the door lock based on the ID signal transmitted using the wireless signal as me medium and a system for controlling the active/inactive state of the vehicle based on the ID signal transmitted using the electromagnetic signal as the medium are needed. In other words, in the vehicle lock apparatus due to coexistence of both systems, the superior facility and the anti-theft function can be compatible.
However, if the wireless signal and the electromagnetic signal are simultaneously sent, the wireless signal and the electromagnetic signal interfere with each other. If the two signals used as the medium sending the ID signal interfere with each other, the ID signal may not be transmitted from the key to the vehicle. Thus, in the apparatus in which both the system for transmitting the ID signal using the wireless signal as the medium and the system for transmitting the ID signal using the electromagnetic signal as the medium merely coexist with each other, an operation failure may occur.
In view of the above point, an object of the present invention is to provide a vehicle lock apparatus having superior facility and a superior anti-theft function, in which apparatus a proper operation state can always be maintained.
A vehicle, lock apparatus to achieve the above object of the present invention has a wireless door look function for remotely controlling a locked/unlocked state of a vehicle and an immobilizer function for switching a state of the vehicle between an active state and an inactive state. In addition, the vehicle lock apparatus comprises a portable transmitting unit for transmitting a first code signal set in accordance with a first method and a second code signal set in accordance with a second method. The vehicle lock apparatus further comprises a wireless door lock unit for switching the locked/unlocked state of the vehicle when the first code signal corresponds to a vehicle code and an immobilizer unit for switching the state of the vehicle from the inactive state to the active state when the second code signal corresponds to the vehicle code, wherein the wireless door lock unit or the immobilizer unit is selectively activated.
In the present invention, the wireless door lock function is established by transmitting the first code signal from the portable transmitting unit. In addition, the immobilizing function is established by transmitting the second code signal from the portable transmitting unit. In a case where the code signal used to establish the wireless door lock function and the code signal used to establish the immobilizing function differ from each other, a high security can be obtained further, in the present invention, the wireless door lock function and the immobilizing function are selectively established. Thus, an operation failure based on the interference between the first code signal and the second code signal is avoided. Thus, according to the present invention, the operation failure in avoided, the superior facility is obtained, and the superior anti-theft function can be established.
Another vehicle lock apparatus to achieve the above object has a wireless door lock function for remotely controlling a locked/unlocked state of a vehicle and an immobilizing function for switching a state of a vehicle between an active state and an inactive state, in addition, the vehicle lock apparatus comprises a portable transmitting unit for transmitting a first code signal set in accordance with a first method and a second code signal set in accordance with a second method and having an internal power supply for supplying a power used to transmit the first code signal. The vehicle lock apparatus further comprises an immobilizing power generating unit for generating a power used to transmit the second code signal when the portable transmitting unit is in a predetermined close state with respect to the vehicle, a wireless door lock unit for switching the looked/unlocked state of the vehicle when the first code signal corresponds to a vehicle code, an immobilizer unit for switching the state of the vehicle from the inactive state to the active state when the second code signal corresponds to the vehicle code, and a wireless inhibiting unit for inhibiting the portable transmitting unit from transmitting the first code signal when the immobilizing power generating unit generates a predetermined power. A communication length for the first code is set at a sufficiently large value.
In the present invention, trio portable transmitting unit is provided with the internal power supply used to transmit the first code signal. Thus, the first code signal can be transmitted under a condition in which the portable transmitting unit is sufficiently away from the vehicle. In addition, the communication length for the first code signal, is long enough. Thus, the wireless door lock function can be established even if the vehicle and the portable transmitting unit are away from each other.
On the other hand, the second coda signal is only transmitted under a condition in which the immobilizing power generating unit can generate a power, that is, a condition in which the vehicle and the portable transmitting unit are in the predetermined close state. Thus, when the vehicle and the portable transmitting unit are away from each other, the first code signal and the second code signal are not simultaneously transmitted from the portable transmitting unit. Thus, the two signals do not interfere with each other. Further, under a condition in which the vehicle and the portable transmitting unit are in the predetermined close state and the immobilizing power generating unit generates a power, the transmission of the first code signal is inhibited. Thus, even it the vehicle and the portable transmitting unit are in the predetermined close state, the interference between the first code signal and the second code signal does not occur. As has been described above, according to the present invention, while avoiding the interference between the first code signal and the second code signal, the wireless door lock function and the immobilizing function can be established in stability.